The present invention relates to a machine and a method for fabricating structural wood components, and more specifically but not exclusively, structural wood joist for use in the construction of building structures.
It is known in the construction of building structures to substitute solid structural wood components by prefabricated components which comprise a plurality of wood pieces interconnected together to provide load support, at least equivalent to solid wood pieces. These prefabricated components have many advantages, such as easy to maneuver, less costly than equivalent solid wood pieces, less expensive to transport, etc. These prefabricated structural wood components, such as joist components, are fabricated from 2xc3x974 lumber pieces which are disposed in specific configurations and interconnected at their junctures by connecting metal plates which are punched to provide a plurality of wood engaging finger projections extending from one surface thereof. These plates are then pressed into the lumber pieces at their interconnecting junctions. Reference is made to some patents which exemplified this art and namely U.S. Pat. Nos. 3,985,278; 3,769,771; 5,285,720 and 4,241,681.
It is a feature of the present invention to provide a novel machine and method for fabricating structural wood components, such as structural joist, for use in the construction of building structures.
According to the above features, from a broad aspect, the present invention provides a machine for fabricating structural wood components. The machine comprises a component assembling jig for assembling pre-cut wood pieces at predetermined positions corresponding to a structural wood component design. Retaining means are provided with the jig to retain wood pieces in position therein. Connector plates are stored in storage means and connector plate positioning means are adapted to position a plurality of connector plates from the storage means, at predetermined locations with respect to the component design and at a fastening location. Each of the connector plates has a plurality of wood engaging finger projections extending from a flat surface thereof. Displacement means is provided for transferring the assembled wood pieces to a clamping transfer platform to hold the assembled wood pieces in contact at interconnecting junctions and transfer the assembled wood pieces to the fastening position with the interconnecting junctions adjacent associated ones of the predetermined locations. Means is provided to secure the connector plates to the wood pieces at the interconnecting junctions to interconnect the wood pieces together to form an assembled structural wood component. Discharge means is provided to discharge the assembled structural wood component.
According to a still further broad aspect of the present invention there is provided a method of fabricating structural wood components and which comprises the steps of disposing pre-cut wood pieces at predetermined positions in a component assembling jig. The pre-cut wood pieces are clamped in the component assembling jig. A plurality of connector plates is positioned at predetermined locations with respect to a wood piece fastening location. The clamped assembled wood pieces are displaced to a transfer position and transferred on a transfer platform by unclamping the wood pieces while maintaining their assembled orientation. The wood pieces are clamped together on the transfer platform and placed in contact at their interconnecting junctions. The transfer platform is displaced to the fastening location with the interconnecting junctions of the wood pieces disposed adjacent associated connector plate positioning means aligned on opposed sides of the structural wood component formed by the assembled wood pieces. The connector plates are then pressed against the assembled wood pieces from opposed side of the interconnecting junction to cause a plurality of wood engaging finger projections of the plates to penetrate into the assembled wood pieces about the interconnecting junctions. The assembled structural wood component is then discharged from the machine.